BELLEFONTE, Pa. — One of the 18 Pennsylvania State University fraternity members charged in the hazing death of Tim Piazza erased security footage that could have shed light on the 19-year-old pledge’s final moments, a lead investigator alleged Thursday.

State College Police Detective David Scicchitano testified that he believed he knew which of the charged young men was responsible for wiping the tapes, although he did not name names.

Prosecutors later added that their investigation into Piazza’s death continues and that additional charges could be filed.

Those twin revelations came as the preliminary hearings for 16 members of the now-shuttered Beta Theta Pi fraternity chapter resumed in a Centre County courtroom in a fourth day of proceedings that have stretched over two months.

The hearing is set to resume Friday, when District Judge Allen Sinclair could issue his decision on whether to allow the unusual prosecution to proceed to trial. In a case that has ignited debate over fraternity culture, hazing, and reckless college drinking, prosecutors have sought to hold criminally responsible nearly everyone connected to a booze-fueled Feb. 4 initiation ritual that left Piazza blackout drunk.

Thursday’s proceedings got off to a tense start as long-simmering tensions between Centre County District Attorney Stacy Parks Miller and supporters of the fraternity brothers boiled over.

Responding to scoffs from the gallery as she urged a defense lawyer, at mid-objection, to “show some respect,” Parks Miller turned her back on the judge and began shouting toward the audience.

“How about the family cool it with the reactions?” she said. Then she turned toward the fraternity members and their lawyers, yelling: “And I’ve had it with you, too!”

But Parks Miller aggressively challenged them at every turn, earning nods of approval from Piazza’s parents seated in the gallery’s front row, while irritating the young, suit-clad defendants and their lawyers with her pugnacious interruptions.

“This whole thing is them trying to blame Mr. Piazza for his death,” she told the judge at one point. “It’s not relevant. It’s not a defense to these crimes.”

Ted Simon, lawyer for Luke Visser — one of eight Beta Theta Pi members facing the most serious charges — stepped up to the defense table early Thursday to become Parks Miller’s latest sparring partner. And, like the lawyers who had come before him, he tried to downplay his client’s role.

Visser, 19, of Encinitas, Calif., didn’t live in the fraternity house and wasn’t there at the time Piazza sustained his fatal injuries during multiple drunken falls that night, Simon stressed in cross-examination of Scicchitano, the lead investigator. According to the presentment in the case, Visser ran a beer-pong station for pledges earlier in the evening.

“You have no evidence that my client ever intended to harm Mr. Piazza,” Simon said. “And you certainly have no evidence that Mr. Visser intended to cause his death.”

Others sought to shift blame away from their clients onto Tim Bream, a 56-year-old Penn State athletic trainer and live-in fraternity adviser, who was at the Beta Theta Pi house the night Piazza sustained his injuries.

Evan Kelly — attorney for Craig Heimer, 21, of Port Matilda — bristled at the fact that Bream had not been charged. He alleged that the man had weekly meetings with the fraternity’s executive board in which he was informed of upcoming parties and had “personally approved” an alcohol-chugging obstacle course that left Piazza unable to stand.

That line of questioning appeared to annoy Parks Miller, who sought to refocus the proceedings on the actions of the 16 young men sitting at defense tables.

“Trust me when I say, if we find anyone that bears any additional criminal responsibility beyond this date, we will charge them,” she said. “So if you have any evidence against him, tell me now, or quit talking about Mr. Bream.”

Lawyers for five of the 18 charged are still awaiting a chance to question the detective. Two Beta Theta Pi members have waived their right to the hearing, and the fraternity chapter itself has been charged as a defendant.

Parks Miller has remained tight-lipped on whether she intends to call any other witnesses before concluding her case.

Prosecutors say the fraternity brothers pressured Piazza to become dangerously drunk and then left him as he tumbled down stairs, stumbled into doors, and was beaten and taunted at the party. The events were caught on harrowing security camera footage from the fraternity house that night.

However, as Scicchitano testified for the first time Thursday, the recordings recovered by investigators early in their probe are missing a key piece — the erased footage from the basement camera.

The deleted video could provide a new vantage point from which to view Piazza’s drunken fall down the basement stairs, believed to have caused some of the injuries that led to his death. It also could shed new light on the actions of others at the party in the main room where they stored most of the alcohol.

Two days after the party, Piazza died of a head injury, a ruptured spleen, and a collapsed lung.